Utility model content
The problem existing for above-mentioned prior art, the utility model provide a kind of can the many distance adjustment of implementation space multi-angle laser induced plasma signal pickup assembly and multi-angle multiple spurs based on this device from spatial discrimination Laser-induced Breakdown Spectroscopy analytic system and analytical approach thereof.
A kind of spatial discrimination Laser-induced Breakdown Spectroscopy analytic system, comprises pulsed laser, transforming laser Focused Optical system, displacement platform, laser induced plasma signal pickup assembly, spectrometer, computing machine; The laser signal that pulsed laser sends arrives displacement platform top after transforming laser Focused Optical system, and spectrometer is connected with pulsed laser, laser induced plasma signal pickup assembly, computing machine respectively; Transforming laser Focused Optical system comprises focused light group; Laser induced plasma signal pickup assembly, comprises clamper and optical fiber probe; Clamper comprises arc-shaped guide rail, slide block and sleeve, has a slide block on arc-shaped guide rail at least, and slide block can slide on arc-shaped guide rail, and slide block central authorities are porose; Sleeve is through the hole of slide block central authorities, can moving radially along arc-shaped guide rail; Sleeve has circular hole, and optical fiber probe is fixed in the circular hole of sleeve; Optical fiber probe comprises collimation lens and optical fiber, and accurate true lens are fixed in sleeve, and optical fiber entrance face is positioned at the focus place of collimation lens.Change the space angle of optical fiber probe by sliding slider on arc-shaped guide rail, change the distance of optical fiber probe and laser induced plasma by the sleeve in moving slider.
Further, described pulsed laser is connected with spectrometer by Time delay unit.
Further, described Time delay unit is pulse delay unit.
Preferably, described Time delay unit also has photoelectric tube, and pulsed laser is connected with pulse delay unit through photoelectric tube.
Preferably, described transforming laser Focused Optical system has reflected light group before focused light group.
Further, on the arc-shaped guide rail of described clamper, be provided with several slide blocks, sleeve is all installed in slide block, optical fiber probe is installed in sleeve.Realizing the multiple optical fiber probes in diverse location place collects the angle of signal and excites the distance independent regulation of position with laser induced plasma.
Further, the rail body of described arc-shaped guide rail is arranged on base, and there is one section of vertical post the junction of arc-shaped guide rail main body and base, and rail body end has block.
Further, the sleeve of described clamper, entirety is square, and sleeve center section has square groove, and the width of square groove is identical with the Circularhole diameter of sleeve.
Further, the optical fiber of described optical fiber probe is step optical fiber, has mechanical interface to connect between collimation lens and optical fiber.
The analytical approach of the utility model spatial discrimination Laser-induced Breakdown Spectroscopy analytic system, the steps include:
The first step, testing sample is placed on displacement platform;
Second step, A. adjust displacement platform, and the laser signal that pulsed laser sends is focused on sample after transforming laser Focused Optical system, inspire plasma;
B. pulsed laser voltage pulse output signal triggering spectrometer in giving off laser beam is started working;
C. the spectral signal that spectrometer is collected laser induced plasma signal pickup assembly converts spectroscopic data to and passes to computing machine for corresponding software analysis;
The 3rd step, regulate laser induced plasma signal pickup assembly, the one, the position of moving slider in arc-shaped guide rail, changes the space angle of optical fiber probe and sample; The 2nd, the sleeve position in moving slider, changes the distance of optical fiber probe and sample;
The 4th step, by regulating the angle and distance of optical fiber probe, reduce background signal, obtain the spectral signal that signal-to-background ratio is higher.
After the 5th step, Computer Analysis, draw the information of sample composition and content.
Further, after described pulsed laser gives off laser beam, Time delay unit triggers spectrometer is started working, and regulates the angle and distance of optical fiber probe, in the time that the spectral signal of laser induced plasma reaches the strongest, gathers spectral signal now.
Further, slide block on described clamper arc-shaped guide rail has multiple, be distributed in the diverse location of arc-shaped guide rail, optical fiber probe on each slide block connects respectively each spectrometer, the multiple optical fiber probes in diverse location place be can realize and the angle of signal and the distance independent regulation with plasma exciatiaon position thereof collected, collect the Laser induced plasma spectroscopy signal of different angles and distance simultaneously, realize multi-angle and analyze simultaneously, analyze diffusion mechanism and the dynamic evolution process of plasma.
The present invention proposes two novel ideas: the one, expand the implication of spatial discrimination, traditional spatial discrimination is mainly relevant with the interior location of optical fiber probe aiming plasma, be actually the utilization of plasma internal nonuniformity, and the multi-angle multiple spurs that the present invention proposes is from spatial discrimination, relevant with respect to the angle and distance of plasma to optical fiber probe, be actually the utilization of the outside nonunf ormity of article on plasma emission spectrum signal; The 2nd, utilize multi-angle multiple spurs of the present invention to improve traditional time resolution LIBS technology from spatial discrimination device, can not only conveniently regulate optical fiber probe, realize multi-angle and analyzed laser induced plasma simultaneously, and strengthened the spectral signal of time resolution LIBS technology from plasma spectrometry receiving side signal face.And the method for tradition enhancing signal is mainly that plasma itself strengthens or changes, strengthen signal from the aspect of plasma light spectrum signal transmitting.
The utility model is simple in structure, can multi-angle, multiple spurs is from the spectral signal that gathers laser induced plasma, by regulating the angle and distance of optical fiber probe, suppress continuous spectrum background, greatly simplify the device of LIBS technology, do not need to rely on time-delay mechanism and locating device, improve and expanded the performance of prior art.
Embodiment
Below in conjunction with accompanying drawing, the utility model is further described.
A kind of spatial discrimination Laser-induced Breakdown Spectroscopy analytic system, comprises pulsed laser 13, transforming laser Focused Optical system 23, displacement platform 18, laser induced plasma signal pickup assembly 19, spectrometer 20, computing machine 21; The laser signal that pulsed laser 13 sends arrives displacement platform 18 tops after transforming laser Focused Optical system 23, and spectrometer 20 is connected with pulsed laser 13, laser induced plasma signal pickup assembly 19, computing machine 21 respectively; Transforming laser Focused Optical system 23 comprises focused light group 17; Laser induced plasma signal pickup assembly 19, comprises clamper and optical fiber probe; Clamper comprises arc-shaped guide rail 1, slide block 5 and sleeve 6, has a slide block 5 on arc-shaped guide rail 1 at least, and slide block 5 can slide on arc-shaped guide rail 1, and slide block 5 central authorities are porose, and sleeve 6 is through the hole of slide block central authorities, can moving radially along arc-shaped guide rail 1; Sleeve 6 has circular hole 9, and optical fiber probe is fixed in the circular hole 9 of sleeve 6; Optical fiber probe comprises collimation lens 7 and optical fiber 8, and accurate true lens 7 are fixed in sleeve 6, and optical fiber 8 entrance faces are positioned at the focus place of collimation lens 7; Displacement platform 18 at least height and position is adjustable; Change the space angle of optical fiber probe by sliding slider 5 on arc-shaped guide rail 3, change the distance of optical fiber probe and laser induced plasma by the sleeve 6 in moving slider 5.
Spectrometer control software and data processing software are installed in computing machine 21, spectrometer control software can be controlled the running parameter of spectrometer, and spectroscopic data storage, spectrogram Presentation Function etc., data processing software is analyzed the spectroscopic data that spectrometer obtains, and can draw qualitative, the sxemiquantitative information of the contained element of sample.
As shown in Fig. 5,7, the principle of this spectroscopic analysis methods is that pulsed laser 13 gives off laser beam, after transforming laser Focused Optical system 23 is turned back on the sample of collimation focusing on displacement platform 18, inspire plasma, pulsed laser 13 voltage pulse output signal in giving off laser beam triggers spectrometer 20 and starts working, the spectral signal that described signal pickup assembly is collected converts spectroscopic data to and passes to computing machine 21 for corresponding software analysis, obtains the information of sample composition and content.In this embodiment, taking spatial discrimination technology as basis, complete the mode of multi-angle multiple spurs from spatial discrimination by laser induced plasma signal pickup assembly, reduce continuous spectrum background, do not need pulse delay unit and Traditional Space in time resolution LIBS technology to differentiate location and the imaging device in LIBS technology, can obtain the signal that signal-to-background ratio is higher, its analysis result as shown in Figure 9.
Further, on the basis of said structure, pulsed laser 13 is connected with spectrometer 20 by Time delay unit 22.
Further, described Time delay unit 22 is pulse delay unit 15, is now internal trigger pattern.
Preferably, Time delay unit 22 also comprises photoelectric tube 14, and pulsed laser 13 is connected with pulse delay unit 15 through photoelectric tube 14, is now external trigger pattern, as shown in Figure 6.
As shown in Fig. 6,8, the principle of this spectroscopic analysis methods is: pulsed laser 13 gives off laser beam, after transforming laser Focused Optical system 23 is turned back on the sample of collimation focusing on displacement platform 18, inspire plasma, under the triggering of Time delay unit 22, spectrometer 20 is started working, the spectral signal that laser induced plasma signal pickup assembly 19 is collected converts spectroscopic data to and passes to computing machine 21 for corresponding software analysis, obtains the information of sample elemental composition and content.System works is trigger mode outside, Time delay unit 22 comprises photoelectric tube 14 and pulse delay unit 15, by give off laser beam scattered light around be converted into electric signal and input to pulse delay unit 15 of photoelectric tube 14 received pulse laser instruments 13, triggering spectrometer 20 starts working, in this embodiment, for time resolution LIBS technology, carry out by laser induced plasma signal pickup assembly the spectral signal that the many Range resolutions of multi-angle can Enhanced time be differentiated LIBS technology, its analysis result as shown in figure 10.
Further, described transforming laser Focused Optical system 23 has reflected light group 17 before focused light group 17, and laser signal is after reflected light group 16 is turned back, on the sample that line focus light group 17 focuses on displacement platform 18.
Further, on the arc-shaped guide rail 1 of described clamper, be provided with several slide blocks 5, slide block can be 2,3,4 or 5, or more, the interior sleeve 6 that is all provided with of each slide block 5, in sleeve 6, optical fiber probe is installed, can realizes the multiple optical fiber probes in diverse location place and collect the angle of signal and the distance independent regulation with sample thereof, as shown in Figure 3.
Further, the arc-shaped guide rail 1 of described clamper comprises base 2, rail body 3 and block 4, base 2 fixed guide main bodys 3, and rail body 3 ends have block 4.One section of the beginning that rail body 3 is fixed on base 2 is vertical post, remainder is arc, arch section ensures that slide block 5 and sleeve 6 can slide into horizontal direction, and arch section one side is middle part hollow out radially, and a side is complete, be convenient to the fixing slide block 5 of bolt, arch section has angle index, and block 4 is square, is fixed on guide-track groove end, restriction slide block 5 sliding scales, also have the effect of fixed guide main body 3.Block 4 has a segment distance apart from the corresponding center of circle of arc-shaped guide rail in the horizontal direction, and this,, apart from ensureing laser beam unobstructed focusing on sample smoothly, is about 2-3cm, as shown in Fig. 1-3.
Further, the sleeve 6 of described clamper, entirety is square, and there is circular hole 9 in sleeve central authorities, and sleeve 6 center sections have square groove 11, and the width of square groove 11 is identical with circular hole 9 diameters of sleeve 6.The circular hole 9 of sleeve 6 central authorities is used for putting optical fiber probe, for the ease of processing, sleeve 6 one sides center section be split into one with the square groove 11 of the same width of Circularhole diameter, only need open circular hole 9 at sleeve 6 two ends, under the prerequisite of conveniently putting into optical fiber probe condenser lens 7, this circular hole is as small as possible, there is the sleeve cap 10 that prevents that sleeve from marking sleeve 6 one end, and the other end can processing screw hole 12 at sleeve 6 sidewalls, is convenient to fixed fiber probe.On sleeve 6, there is distance scale, the distance in instruction sleeve 6 centers of circle corresponding to arc-shaped guide rail, fixed fiber probe condenser lens screw 12 centers, one end (being also that sample surfaces laser induced plasma excites position).
Further, the optical fiber 8 of described optical fiber probe is step optical fiber, has mechanical interface to connect between collimation lens 7 and optical fiber 8, ensures that optical fiber 8 entrances are positioned at the focus place of collimation lens 7.
The parameter of described pulsed laser 13 is wavelength 1064nm, maximum impulse energy 190mJ, and pulsewidth 7-9ns, maximum repetition rate 20Hz, energy hunting is less than 1.5%, and beam divergence angle is less than 1.5mrad, and beam diameter is 5mm.
Described photoelectric tube 14 is fast photodiode, use be PIN silicon photoelectric diode, spectral response range is 200nm-1100nm, the rise time is 1ns, output voltage is about 1-6V, adopts bnc interface output.
Described pulse delay unit 15 converts the voltage signal of photoelectric tube output the square-wave signal of adjustable-3 to+4 to, and time delay output, time delay scope between 0-999s, time delay resolution is 5ps, adopts bnc interface output.
The reflected light group 16 that described transforming laser Focused Optical system 23 is made up of three catoptrons light path of turning back, the focused light group 17 laser focusing bundles that formed by the plano-convex quartz lens of focal length 100mm, bore 25.4mm.Beam diameter after focusing is less than 0.5mm, and laser power density is about 2.5GW/cm2.
Described displacement platform 18 is XZ two-dimension displacement platform, and resolution is 50nm, is 5cm in the range of adjustment of X and Z direction.
Described spectrometer 20 is micro fiber spectrometer, and spectral detection scope is 220nm-325nm, and resolution is less than 0.15nm, and detector is line array CCD.This micro fiber spectrometer the shortest integral time of 1.1ms, the longlyest can arrive 20 seconds.
Described optical fiber probe is made up of collimation lens 7 and optical fiber 8, and collimation lens is plano-convex quartz lens, and bore is 5mm, focal length 10mm, and optical fiber is step optical fiber, and numerical aperture is 0.22, and optical fiber core diameter is 200 μ m, and length is 2m.
The analytical approach of the utility model spatial discrimination Laser-induced Breakdown Spectroscopy analytic system, the steps include:
The first step, testing sample is placed on displacement platform 18;
Second step, A. adjust displacement platform 18, and the laser signal that pulsed laser sends is focused on sample after transforming laser Focused Optical system, inspire plasma;
B. pulsed laser 13 voltage pulse output signal triggering spectrometer 20 in giving off laser beam is started working;
C. the spectral signal that spectrometer 20 is collected laser induced plasma signal pickup assembly 19 converts spectroscopic data to and passes to computing machine 21 for corresponding software analysis;
The 3rd step, regulate laser induced plasma signal pickup assembly 13, one, the position of moving slider in arc-shaped guide rail, changes the space angle of optical fiber probe and sample; The 2nd, the sleeve position in moving slider, changes the distance of optical fiber probe and sample, carries out multi-angle, multiple spurs compartment analysis;
The 4th step, by regulating the angle and distance of optical fiber probe, reduce background signal, obtain the spectral signal that signal-to-background ratio is higher.
After the 5th step, Computer Analysis, draw the information of sample composition and content.
Further, after described pulsed laser 13 gives off laser beam, Time delay unit 22 triggers spectrometer 20 and starts working, and regulates the angle and distance of optical fiber probe, in the time that the spectral signal of laser induced plasma reaches the strongest, gathers spectral signal now.
Further, slide block 5 on described clamper arc-shaped guide rail 1 has multiple, be distributed in the diverse location of arc-shaped guide rail 1, optical fiber probe on each slide block 5 connects respectively each spectrometer 20, the multiple optical fiber probes in diverse location place be can realize and the angle of signal and the distance independent regulation with plasma exciatiaon position thereof collected, collect the Laser induced plasma spectroscopy signal of different angles and distance simultaneously, realize multi-angle and analyze simultaneously, analyze diffusion mechanism and the dynamic evolution process of plasma.
Experiment parameter is, the pulse energy of pulsed laser is 36mJ, repetition frequency is 1Hz, regulate the height of displacement platform to make the sample surfaces on displacement platform slightly higher than the focus of focused light group (for single plano-convex lens), be set integral time on computing machine spectrometer control software is 3ms, and make the each measurement point on sample play 10 pulses by software setting, by a spectrogram of average ten spectrum output.Other experiment parameters are that analytic sample is aluminium alloy, by adjusting displacement platform, can provide new surface, measures and carries out in atmospheric air, the atom line 308.22nm that selected analysis spectral line is Al and 309.27nm and ion line 281.62nm.
Multi-angle multiple spurs for time resolution LIBS technology is operated in external trigger pattern from spatial discrimination Laser-induced Breakdown Spectroscopy analytic system, adjust position and the angle of the relative pulse laser beam of photoelectric tube, can trigger pulse chronotron, the time delay that pulse delay unit is set is 1.4 μ s, add the inherent delay 1.28 μ s of spectrometer, actual total time delay is 2.68 μ s.Measured the same spectrum apart from different angles place, distance is respectively 15mm, 30mm, and 45mm, 50mm, each distance takes measurement of an angle and is respectively 15 °, 22 °, 33 °, 39 °, 45 °, 50 °, 56 °, 60 °, 64 °, 67 °.Experimental result, as shown in Figure 9.Also measure similarly the spectrum at same angle different distance place, angle is respectively 39 °, 45 °, 50 °, 60 °, and the distance at each angle place is respectively 12mm, 15mm, 20mm, 30mm, 35mm, 40mm, 45,50mm, 55mm, 60mm, 65mm, 70mm.Analyzing these data can find out: for the multi-angle multiple spurs of time resolution LIBS technology from spatial discrimination Laser-induced Breakdown Spectroscopy analytic system, on signal pickup assembly, regulate the angle and distance of optical fiber probe collection signal to desired value, can strengthen the spectral signal of the plasma of analytic system; The scope of the optical fiber probe angle and distance that this experiment obtains is, angle is about 50 °, and distance is about 15mm-35mm, and best angle is substantially fixed in different distance, on best angle, in the distance of relative broad range, can obtain stronger signal.
In spatial discrimination Laser-induced Breakdown Spectroscopy analytic system for spatial discrimination LIBS technology, do not have after photoelectric tube and pulse delay unit, directly trigger spectrometer with laser instrument, the pulse voltage signal of the inner output of laser instrument 98 μ s before laser beam output send, with respect to laser beam, the time delay of the pulse voltage signal of laser instrument is-98 μ s, spectrometer internal delay time is about 1.28 μ s, and total time delay on historical facts or anecdotes border is-96.72 μ s, has covered the initial stage of plasma generation.Measure the situation of change of multiple angles place spectrum with distance, take measurement of an angle and be respectively 33 °, 39 °, 45 °, 50 °, 56 °, 60 °, the distance at each angle place is respectively 12mm, 15mm, 20mm, 30mm, 35mm, 40mm, 45,50mm, 55mm, 60mm, 65mm, 70mm.Although there is no photoelectric tube and pulse delay unit, do not take time delay measure, spectrometer has covered the initial stage of the plasma generation that continuous background is stronger integral time, but by many distance adjustment of multi-angle laser induced plasma signal pickup assembly adjusting angle and distance, still background can be obtained lower, the spectrum that signal-to-background ratio is higher, as shown in figure 10.Can find out by analyzing data: for many distance adjustment of multi-angle spatial discrimination Laser-induced Breakdown Spectroscopy analytic system of spatial discrimination LIBS technology, conditioning signal harvester makes the angle and distance of optical fiber probe collection signal in OK range, do not need photoelectric tube and pulse delay unit, utilize the pulse voltage signal of laser instrument output directly to trigger spectrometer, use and cover plasma generation initial stage and longer integral time, can reduce the continuous background of spectrum, obtain the plasma signal that signal-to-background ratio is higher; In this experiment, the scope of optical fiber probe angle and distance is, angle is about 40 °-55 °, and distance is about 40mm-55mm, and the angle and distance of optical fiber probe is arranged in pairs or groups, a corresponding best distance of angle.
The analytical effect of the utility model analytic system and analytical approach thereof is good, advantage highly significant:
1. for time resolution LIBS technology, collect the angle of signal and the distance with plasma exciatiaon position by fine adjustment optical fiber probe on the laser induced plasma signal pickup assembly in described analytic system, obtain the peak signal of Laser induced plasma spectroscopy, the signal of having realized easily time resolution LIBS technology strengthens.
2. on the diverse location by the signal pickup assembly arc-shaped guide rail in described analytic system, multiple optical fiber probes are set, the angle and distance of each optical fiber probe is independently controlled, collect the Laser induced plasma spectroscopy signal of different angles simultaneously, can realize the multi-angle of laser induced plasma is analyzed simultaneously, realize the analysis of diffusion mechanism and the dynamic evolution process of plasma.
3. for spatial discrimination LIBS technology, collect the angle of signal optical fibre probe and the distance with plasma exciatiaon position by regulating easily the signal pickup assembly of described analytic system, do not need pulse delay unit and Traditional Space in time resolution LIBS technology to differentiate location and the imaging device in LIBS technology, do not need specific time delay and time shutter or optical fiber probe to locate accurately aiming, can reduce background, obtain the spectral signal that signal-to-background ratio is higher.
The accurate quantification of having realized optical fiber probe by the laser induced plasma signal pickup assembly of described analytic system thus regulates, and has strengthened the analytical performance of existing time resolution LIBS technology under the condition that there is no additionally to increase device.And realized multi-angle collection signal simultaneously, analyze diffusion mechanism and the dynamic evolution process of plasma.The most important thing is, this analytic system and analytical approach do not need pulse delay unit and the Traditional Space in time resolution LIBS technology to differentiate location and the imaging device in LIBS technology, reduce the background of continuous spectrum by multi-angle multiple spurs from the mode of spatial discrimination, fully overcome the shortcoming of time resolution LIBS technology and Traditional Space resolution LIBS technology.This analytic system and analytical approach device are simple, easy to use simultaneously, and analytical effect is good.
Obviously, above embodiment is only to the utility model example, and the not restriction to the utility model embodiment.To those of ordinary skill in the art, can also make other changes in different forms on the basis of the above description.Here without also giving exhaustive to all embodiments.And these belong to apparent variation that spirit of the present utility model amplified out or variation still among protection domain of the present utility model.